ioquake3 is a free software first person shooter engine based on the Quake 3: Arena and Quake 3: Team Arena source code. The source code is licensed under the GPL version 2, and was first released under that license by id software on August 20th, 2005. Since then, we have been cleaning it up, fixing bugs, and adding features. Quake 3 Arena was specifically designed for multiplayer. The game allows players whose computers are connected by a network or to the internet, to play against each other in real time, and incorporates a handicap system. It employs a client–server model, requiring all players’ clients to connect to a server. Quake III Arena’s focus on multiplayer gameplay spawned a lively community, similar to QuakeWorld, that is active to this day.